Sorry Jimmy, but this reply is very strange. If anything, you help to prove my point.
This Mayo team are unquestionably in decline - the perfect illustration of why you can't expect a side with a significant number of 30+ players to remain competitive at the top level. No Connacht titles in four years and a failure to make the last eight in 2018. They will also very possibly bow out before the Super 8s again this year.
The Monaghan side that started last year's All Ireland semi-final had maybe two players in their thirties - Corey and Mone. The rest of their side aren't much older than our current side. Conor McManus and Darren Hughes are the same age as Jamie Clarke and Mark Shields. Colin Walshe, Keiran Hughes, Dermot Malone and Keiran Duffy all played minor football the year before our 2009 minor group. Rory Beggan, Ryan Wylie, Ryan McAnespie are younger still. Despite a lot of men only touching their thirties, this Monaghan team are already look past their best.
And of the five Dublin men you name, only two start regularly. The others are bit part players, already replaced in the starting team by younger models (although McManamon nor Andrews never really held down starting places). If anything, Dublin are the prime example of the importance of youth in the modern game. They continually refresh their side with younger players so that they don't have to rely on men into the twilight of their careers.
I'm not really trying to pick faults here, I'd love it if Jamie Clarke and Stefan Campbell are still kicking three or four points a game at 34. But realistically, that is unlikely. I thought it was important to highlight the age profile of the current side in this discussion, particular in light of many of the comments here and elsewhere in recent days made by those who seemed to be under the impression that we have a young team with most players a few years away from their peak. That's just not the case.